1) Understand the game you are playing 

• The inner game - it is played within the mind of the player, and it is played against such obstacles as: lapse in concentration, nervousness, self doubt, self condemnation.
• Don’t try and play the game of perfection, or you will always be unhappy. And don’t compare yourself to others, there will always be others that would make you feel inferiority. Don’t compete on image: you can never look good enough, and good to everybody.
• What does it mean to win the inner game? I think it is the most important question. 

2) Relaxed concentration over thought 

• Visualize what and where you want: where you want the ball to go, see it, and, if you like, shut your eyes and imagine yourself doing it. Then don’t think and try; just ask your body to do whatever is necessary to do it.
• Pay attention to the different details and variables and see what feels like it works and what doesn’t. Really observe what you’re doing. Watch it with care, and it will change quite effortlessly.
• Focus means not letting your mind run away with you. Watch a tennis ball in all its detail without thinking about worries, hopes, or instructions. In short, we worry too much and concentrate too little.
• Stress is a thief that, if we let it, can rob us of the enjoyment of our lives. Letting go of my grip on life released an energy that made it possible for me to run with utter abandon toward life.
• Trust in the intelligence of your body and mind, and let it swing. Don’t try to think through it, or you will over-tighten and become rigid, interfering with the wisdom of the body. Let it happen if it knows, and let it learn if it doesn’t. Remember as precisely as possible the feel of a good shot, action, or moment.

3) Use difficulty to discover your potential

• It is only against the big waves that a surfer is required to use all his skill, courage, and concentration to overcome them. Only then can he realize the true limits of his capacities. The more challenging the obstacle he faces, the greater the opportunity to discover and extend his true potential.
• The potential may have always been within him, but until it is manifested in action, it remains a secret hidden from himself. Obstacles are a necessary ingredient in this process of self-discovery. The surfer is exploring his latent capacities through the process of trying to overcome the wave. The process can be more rewarding than the victory itself.

4) Closing thought

• The most impactful part of the book for me were the occasions the author would describe of a coaching session where someone would come to him after struggling with say a poor backhand or serve. They would have taken multiple other lessons, been given many instructions (foot weight here, start moving the racket at this time, wrist should snap like this, etc.), to little avail.
• The author would then, without giving a single piece of instruction, guide the person on really paying attention to their stroke, and giving them time to realize what motions worked and didn’t. By halfway into the lesson, they would have self-discovered the stroke that worked for them, changing their game more in 30 minutes than 3 years of lessons prior. 
• When they would thank him after the lesson, he would say “for what exactly? I don’t think I told you a single thing..."